1. Field of the Invention
The present invention relates to a rigid sleeve device for an endoscope which can be applied to a flexible endoscope for use in inspecting the interior of, for example, a jet engine and for other industrial fields of art.
2. Description of the Related Art
Generally, there are two types of endoscopes one having a rigid and the other having a flexible insertion section. In the case where an endoscope can gain access to a region of interest with its insertion section straight, a rigidoscope with a straight rigid insertion section is suitable in view of its ready accessibility to the region of interest and hence the easiness of an inspection operation. In the case where, for example, inspection is to be made on the turbine blades of the jet engine, a rigidoscope is preferably used, in place of a flexible endoscope, due to its ready handling capability in which case it is inserted through an inspection hole in the outer wall of the engine.
However, the rigidoscope is unsuitable when inspection is made on an inaccessible, not-straight inner space. In this case, the flexible endoscope is indispensable. Jpn. UM Appln. KOKOKU Publication No. 3-40241 discloses an outer sheath fitted over an insertion section of an endoscope. The outer sheath for the endoscope is fitted over a flexible insertion section and, in this case, the outer sheath is fixedly mounted on a proximal operation body of the endoscope. A means for mounting the flexible sheath relative to the proximal operation body of the endoscope provides a coupling means by which the base end of the outer sheath and the proximal operation body are combined together and fixed together. The length of the outer sheath corresponds to the insertion length of the endoscope.
Depending upon the inspecting situations, there are cases where inspection has to be made properly using both the flexible endoscope and the rigidoscope. In this case, the inspecting personnel selectively uses these two endoscopes according to the object of their uses. Therefore, it was necessary for the user to initially possess the two types of endoscopes or prepare both.
With the outer sheath in use, a corresponding detachable mount means is necessary to join the outer sheath to the endoscope and, in this case, a compatible relation is required between the outer sheath and the endoscope. This restricts the types of associated outer sheaths.
Further, outer sheaths of various lengths are required in those applications demanding varying lengths. Therefore, many endoscopes and outer sheaths have to be prepared to meet these situations, incurring added management and installment costs.
Further, although the rigidoscope is suitable for accessing, for example, the turbine blade of a jet engine, the inspection holes in the jet engine are provided at various angles around the engine and, when the rigidoscope is inserted into the inspection hole, the inspecting personnel suffers overstrain in his assumed position and hence physical pain.